The Cuyuna Iron Range is a former North American iron-mining district about ninety miles west of Duluth in central Minnesota. Iron mining in the district, the furthest south and west of Minnesota’s iron ranges, began in 1907. During World War I and World War II, the district mined manganese-rich iron ores to harden the steel used in wartime production. After mining peaked in 1953, the district began to focus on non-iron-mining activities in order to remain economically viable.
In the early 1880s, federal surveys noted magnetic anomalies near what would become the Cuyuna Range. No visible outcrops of iron ore were present at the surface. Henry Pajari and Cuyler Adams realized these magnetic anomalies could be buried iron ore deposits. Pajari was quickly frustrated in his search effort. Adams carefully mapped ore deposits over the next twenty years. By 1902, Adams began seeking outside investors to develop mines near the best locations.
In June 1907, Adams and his business partners enticed the Rogers–Brown Ore Company to open the Kennedy Mine, the first active iron mine on the Cuyuna Range. In 1907, the nearest town was too distant from the richest iron ore deposits. Adams bought and sold land to developers near the largest iron deposits for new towns. Around 1910, immigrants from northern and southern Europe settled into newly built mining communities with the hope of finding work at mines.
Demand for iron ore in the United States surged during World War I. Over thirty iron mines were operating at that time; most were underground operations. After the war, many of these Cuyuna Iron Mines closed. The few new mines of the 1920s were open pits that used large earth-moving equipment rather than shafts and tunnels to reach the ore.
The Milford Mine was a struggling underground mine. On February 5, 1924, water from an adjacent lake rushed into the underground tunnels, killing forty-one miners within minutes. The official investigations into the disaster found no individual or company to be at fault. The report stated that hidden geologic features near the lake were weakened by tunneling and allowed the water to drain into the mine suddenly.
By the early 1930s, the economic woes of the Great Depression affected mining in the Cuyuna Range. In 1932, the citizens of Crosby, the largest community in the region, elected Karl Emil Nygard as the first Communist Party mayor in the United States. Nygard’s city council opposed many of his relief policies. He spent much of his time stating his accom-plishments in speeches at political rallies outside the Cuyuna Range. In 1933, he lost his reelection bid.
By the early 1940s, demand for Cuyuna Iron ore peaked. Manganese-rich iron ores were important for making very hard steels. The Cuyuna Range held the largest domestic supply of this ore. Demand for iron and steel continued throughout World War II and the Korean War. In 1953, production on the Cuyuna Range reached its highest point, at a little over three-and-a-half million tons. In that year, producing other resources, like manganese, also became a priority. The Manganese Chemical Corporation, based in Riverton, researched new methods to turn manganese ore into products for modern batteries. The patents filed for this process continue to be cited by major battery companies in the twenty-first century.
The early 1960s saw a rapid decline in iron ore from the Cuyuna Range as seventeen mines closed between 1961 and 1965. The Manganese Chemical Corporation moved from Riverton to Baltimore, Maryland, in 1962. The passing of the Minnesota Taconite Amendment in 1964 incentivized production from other Minnesota iron ranges. By 1967, the last operating underground mine in Minnesota, the Armor #2 Mine near Crosby, was closed. By 1982, the last reported shipment of iron ore from the Cuyuna Range was made, ending the period of active mine operations in the district.
In 1993, local and state representatives created a new type of park in Minnesota from the former mine lands of the Cuyuna Range. The Cuyuna Country State Recreation Area contains most of the former mining landscape in the Cuyuna Range. This park attracts visitors that hike and bike along former mine roads and piles of overburden.
For more information on this topic, check out the original entry on MNopedia.